Sorry this information is a little late. I've been busy with other stuff. I
will be going to the North Shore of Minnesota, July 26-29 . I'm hoping to
activate a few grids on this trip. Grids will probably be EN47, EN46, or
around those grids. I will only be doing AO-91 and AO-92 satellites, and
maybe some SO-50. This will be a relaxing trip, so I will get on the
satellites when I can. Thanks everybody!
73 de W0AAE
I really like Walters’ idea of having an HT only (or QRP) time for
an FM satellite.
Once a week or even month would be fine. I have special memories
of using my TH-D72 with a long whip getting into AO-91 and working
ZL3GAV (from RF73 to RE66) back in 2018.
My thought is this non-QRO time would allow new-to-sat hams and those
testing portable equipment an opportunity to experience the wonder of
satellites without having to wedge themselves between other QSOs.
And to Walters’ final comment about operating with an HT and an Arrow
That was my experience for two years with ONLY SO-50 available and a
Yaesu FT-530 running 2.5 watts. The competition for SO-50 was intense
with other rovers and QRO stations.
Hector (congrats GridMaster #13) suggested I use a larger battery for
full 5 watts from the FT-530. This could be one of potential results
for an operator using this ’special’ time for HT-only FM sat usage.
73 and Dream On Walter. Great idea!
Hi Bob and Nico,
I want to add some info about this problem.
If You have the ARRL Satellite Handbook, see page A-8 (Appendix A -
There is Equation 13a, which give us the value - rate of change of
argument of perigee in degrees per day.
The value for RS-44 with current TLE data is -2.3331333 degrees per day.
A negative value means that the ARGP angle will be smaller tomorrow.
For example 180 degrees divided by -2.3331333 is approx. -77.1495471 days.
So, in 77.15 days the positions of the apogee and perigee will be swaped.
And yet, if we have apogee in the best position for some rare qso with
RS-44 transponder, this situation will be repeated 2.366 times per year.
360/2.3331333 = 154.2989
and 365 days / 154.2989 is 2.366
With the same equation 13a we can calculate the famous angle of 63.435
degrees of inclination with zero drift as Nico says. This angle was used
by the old Russian Molnia satellites at a time when it was still
difficult to reach a geostationary orbit.
My favorite FO-29 (now probably nice history) has Rate of change ARGP
Yet, AO-91 with elliptical orbit (apogee 811.8 km /perigee 453.6 km) has
Rate of change ARGP = -3.251476 degrees/day, so it takes -55.359 days
for exchange apogee and perigee positions..
It is very good to check the ARGP angle in the TLE data when working via
elliptical orbiting satellites.
For example, for the qso between the eastern costs of the USA and
Europe, we need an orbit height of approximately 950 km (for OK
stations). FO-29has an apogee height of 1320.8 km, perigee 801.2 km. It
was not possible to make with the apogee in the wrong position
This email has been checked for viruses by AVG.
Hi-RS44 varies in altitude from about 1180 to about 1525. Seemingly always in the southern hemisphere. I'm trying to wrap my head around the orbital mechanics and getting nowhere. Does the maximum height ever get to the northern hemisphere? I'm obviously missing something here, a little help please.
73 Bob W7LRD
Quoting Walter Holmes via AMSAT-BB who wrote on Sat 2020-07-25 at 00:49:
> Any idea what the chances would be of having something like 1 night a week or month, on ONE of the FM birds, that could be reserved for HT access only?
> My thinking on this would be a great way for people to test out their portable or limited satellite stations with a great deal less collisions against all the other much stronger stations.
> I have heard from plenty of people that would like to try a temporary or portable station on the birds, but we all know that’s not even a remote possibility unless your on super early in the morning or late at night.
As it happens I was trying a new radio for a portable setup last evening
(I bought a KG-UV1K to get full-duplex capabilities).
On a not-to-high pass yesterday evening (max 21 degrees elevation with lots
of buildings around) I did hear AO-92 and could understand some of the
callsigns, but could not get in at all. Mister Ollaaaa was also active on
some occassions. I will try again on a higher pass.
My plan is to bring it along on an upcoming holiday, which will be in a
somewhat rare grid. But since it's a holiday and I'm not sure when a pass
will be at a usable time, I'm not going to announce it as an activation. I
may just make a few contacts.
So I'm the 'target audience' for your idea, and I really think it's a good
Amateur station PE4KH
I just renewed membership and request information about compatibility on my radio ( IC-2730A ) for working the FM birds.
I was hoping to use my IC-2730A along with HRD but cannot find a CAT cable for compatibility. HRD lists the 2730 as an available radio but no joy connecting.
I am hoping to connect with someone that IS or HAS used this radio with or without HRD for help.
If this is NOT a viable radio, please notify me!